The present invention relates to a motor apparatus.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Applications in which extremely high forces and/or torques are required have to resort to motors that have distributed winding systems. This is the case, for example, in segmented motor applications or when linear and torque motors are connected in parallel, but also, for instance, for spindle motors having two winding systems. These applications use inverters which each work effectively in parallel and which each control one winding system and require a dedicated encoder in order to obtain position information regarding the relative position of its active parts (e.g. stator to rotor).
In previously implemented applications, a segmented motor is operated in a type of master-slave configuration. For this purpose, the first motor module, which contains an inverter or power converter, in particular a frequency converter with intermediate voltage circuit, is the master in controlling the speed, and all the further motor modules, which likewise contain a power converter or inverter, are operated as torque slaves. The same applies to high-power linear motors and torque motors operated by a plurality of motor modules. Examples here may be dual-chamber applications or large, extremely rigid cast-iron pivot axes. It is also possible as an alternative to use a higher level controller for true master-slave operation using a torque-compensation controller.
Until now it was necessary for each motor module to use a dedicated encoder to obtain an individual item of position information for the commutation, with each encoder being connected to the motor module via a corresponding sensor module. For this purpose usually either a plurality of encoder heads (one for each motor module) are mounted on a shared physical measurement reference or only one reading head is used and the encoder signal is duplicated via an encoder splitter. The duplicated encoder signals are then each provided to the relevant inverter via a sensor module.
It would therefore be desirable and advantageous to provide a simpler design of a motor apparatus having a plurality of winding systems and a corresponding method for a simple control of such a motor apparatus.